Scanning device



Nov. 12, 1946. L. A. MAYBARDUK EIAL 2,410,831

SCANNING DENlECE Filed April 10, 1942 4 Sheets-$heet 2 93 an em 'INVENTORS, LAMAYBARDUK, WJMMIEHER,

' S.J.ZAND and G E.WHlT-E,

THEIR AITEY'.

' 194st L. A. MAYBARDUK EI'AL I 2,410,331

SCANNING DEVICE Filed April 10 194 2 4 Sheets-Sheet 5 Clulch Conhol Brake Conhol INVENTORS, L.A.MAYBARDUK, wWMlEHER.

S.J.ZAND and GE. H Ti? Nov. 12, 1946. L. A. MAYBARDUK ETAL 2,410,831

SQANNING DEVICE Filed April 10, 1942- 4 Sheets-Sheet 4 INVENTORS,

L. A.MAYBARDUK,W.WMIEHER,

THE-IR ATTORNEY.

Patented Nov. 12, 1946 UNITED STATES PATENT.

FFlCE SCANNING DEVICE Application April 10, 1942, Serial N0. 438,388

29 Claims.

The present invention m concerned with devices for scanning a beam 01 fadiant energy, or scanning a directive reception pattern over a predetermined solid angle.

In many applications, such as in object detector, distance measuring, and radiolocating devices, it is desirable to scan a projected beam of radiant energy over a predetermined solid angle usually conical in form in order that the presence and/or distance of a distant object located within that solid angle may be detected and measured by associated apparatus, In such systems it may also be desirable, after such an object has been detected, and its presence indicated, to directly orient the radiant energy transmitting system toward the distant object in order to accurately indicate its orientation, relative to the location of the transmitting system.

According to the present invention such a device is provided, adapted to scan a predetermined conical angle up to and including a complete hemisphere by means of a spiral conical motion of a sharply directed radiant energy beam. This motion is provided by rapidly spinning the radiating system about one axis while slowly nodding the system about a second axis perpendicular to and rotating with the first axis.

In addition to such a spiral scanning or searching operation it is desirable in some systems to convert the spiral scanning, which is generally eiiective over a wide solid angle, to a type of circular conical scannin having a very narrow apex angle, such as of the order of 2 to 8 degrees, whereby the actual orientation of th distant object may be accurately indicated by suitable indicating systems, such as are shown in copending application Serial No. 441,188, filed \April 30, 1942, for Radio gun control system in the name of G. E. White, C. G. Holschuh, W. W. Mieher and J. E. Shepherd. Such a change from spiral to circular scanning may be produced in the present device by interrupting the nodding motion at a point in its cycle at which the axis of the radiated beam is at an angle to the spinnin axis equal to, half the desired apex angle of the circular scanning, while retaining the spin motion. In the illustration used above this might be, for example, 4 degrees. In this manner,- by interrupting the nodding motion and maintaining the spinning motion, the beam is caused to move in a narrow circular conical pattern as desired.

It is further desirable to be able to adjust or vary, in elevation and azimuth, the general orientation of the radiating system, which may be taken to be the orientation of the pole of the spiral scan or the axis of the circular scan, both coinciding with the spin axis, in order that the radiating system may have its center directed in any desired orientation within the range of the system. For this purpose the spinning axis of the radiating system may be made adjustable both in azimuth and elevation, whereby either the circular scanning or the spiral scanning may be directed toward any point of the sphere within the limitations of the system.

Alternatively, such orientation may be desired only during circular scanning, to provide tracking with the distant reflecting object. Then either or both the nod and spin axes may be alternatively used, during circular scanning, as the elevation and azimuth axes, respectively. In such case, the spin motion may be interrupted at the proper point, and the radiating system may be then rotated about a further axis slightly angularly displaced from the beam axis, to thereby provide the circular tracking scanning. Thereafter, the new axis may be oriented in elevation and azimuth by the use of the nod and former spin axes as elevation and azimuth axes, or by independent elevation and azimuth axes.

According y, its is an object of the present invention to provide improved devices for sweeping an orientable member over a predetermined solid angle of space.

It is another object of the present invention to provide improved radio scanners for spirally sweeping a directive radiation pattern over a conical solid angle.

It is a further object of the present invention to' provide improved devices for converting one kind of scanning to a difierent type.

It is still another object of the present invention to provide improved devices for alternatively scanning spirally or circularly.

It is a still further object of the present invention to provide improved scanners for alternatively scanning spirally, as for searching, or circularly, as for tracking, and for adjusting the scanning axis orientation.

It is yet another object of the present inven tion to provide improved scanning devices adapt ed to produce spiral scanning of an orientable member by a combination of nodding and spinning motions of this member, and to convert to circular scanning by interruption of the nodding motion.

It is still another object of the present invention to provide improved spiral scanning of an orientable member by a combination of nodding and spinning motions of this member, and to nvert to circular scanning by interruption of the inning motion and initiation of a new spin- ,ng motion.

Further objects and advantages will become Jparent from the following specification and rawings in which Figure 1 comprises a perspective view of one mm of scanner, embodying independent azimuth id elevation controls.

Figure 2 comprises a perspective view of a modied form of scanner in which the nod and elevaon axes are combined. 1

Figure 3 is a wiring diagram of a suitable conol circuit for the scanner of Figure 2 for ef- :cting changeover from spiral to conicalscanlng.

Figure 4 is a wiring diagram disclosing a modization of the control circuit of Figure 3.

Figure 5 is a perspective view showing a furier modification of the scanner of Figure 2, comvning the spin and azimuth axes.

Figure 6 is a wiring diagram of a control ciriit for the scanner of Figure 5.

Figure 7 is a perspective view of a controller rr determining the point at which the scanner Figure 5 is to convert from searching to 'acking.

Figure 8 is a wiring diagram of a control circuit )r use with the scanner of Figure 5 and conoller of Figure 6.

Figure 9 is a diagrammatic view of a modificaon of the scanner of Figure 5.

Referring to Figure 1, a supporting mount I pivotally supported about a vertical axis 3, s on a suitable step or thrust bearing 5 mounted n a fixed support I. Support I also carries fixed it a horizontal gear 9 which engages with a inion mounted on a shaft I3 journaled in iount I as by a suitable bearing l5. Carried on ie supporting mount is a suitable variable seed driving mechanism, illustrated in this in- ;ance as being of the variable-displacement hyraulic transmission type, comprising an electric riving motor I'I driving two units I8 and 20 comrising respective variable displacement pumps "hose fluid outputs actuate respective hydraulic rotors and thereby rotate the respective output Crafts I9 and 2|.

One of these units, such as I8, is adapted to Jtate the radiating system in elevation, as will e seen, and the other unit, such as 20, is adapted rotate the system in azimuth. The output oeeds of shafts I9 and 2| are under the control I? a suitable control box 23 adapted to control 1686 shafts I9 and 2| under the influence of a emote controlling station, Such a control box my assume the form shown in copending aplication Serial No. 417,580, for Remote aircraft irret control mechanism, filed November 1, 1941, 1 the name of W. C. Hartman, J. A. Peoples, Jr., nd H. L. Hull. The control station may be any rientable device, such as a telescope, gun sightomputer, search-light, etc, or any suitable conrol for producing control signals to actuate conrol box 23 Any other type of actuating device may be used, E desired, with any suitable type of control, acording to the requirements of a particular apilication.

Azimuth shaft 2| is coupled directly to shaft I3 s by suitable gearing 25.v In this Way upon aetu- ,tion of the azimuth unit 20, pinion I I is caused o rotate and thereby causes the supporting count I and the radiating apparatus to walk .round the fixed azimuth gear 9. The azimuth gear 9 is preferably made in the form of a semicircle in order to clear the path for scanning in a downward direction, as will be apparent from the description below.

Pivoted in supporting mount I about a normally horizontal axis, such as axis 21 intersecting azimuth axis 3, is a housing 29 which carries the radiating system and its spinning and nodding operating mechanism. Fixed to the pivot axis of housing 29 is a worm wheel sector 3| driven from a worm 33 which in turn is energized from the elevation output shaft I9 as by way of gearing 35, shaft 31, and gearing 39. In this way, upon energization of elevation control unit I8 and actuation of the output shaft I9, the housing 29 is caused to rotate about a horizontal axis. By the above mechanism, therefore, housing 29 is adapted to be rotated both in elevation and azimuth and may, therefore, be oriented in any desired direction.

Mounted on supporting mount I is a driving motor 4| whose output shaft 43 is preferably made concentric with the horizontal pivot axis 21 of housing 29. If desired, motor 4| may be mounted anywhere on housing 29. Shaft 43 passes through a suitable bearing in housing 29 and drives, as by way of gearing 44, a bevel gear 41 which in turn actuates a further bevel gear 49 and a shaft 63 fixed thereto. Shaft 53 drives a large gear 48 through pinion 45, Gear 48 is mounted in housing 29 for rotation about spin axis 5|, which is preferably chosen to intersect both elevation axis 21 and azimuth axis 3.

Fastened to gear 48 as by a hub 5| is a yoke 53 which, as will be seen, carries the nod axis 55 about which is pivoted a member 51 carrying the directional radiating system illustrated as comprising a parabolic reflector 59. Nod axis 55 preferably intersects spin axis 6|. In this way, power motor 4| supplies the driving power for spinning the parabola 59 about the spin axis 8|. The nodding motion of the parabola 59 is-actua-ted from the spinning motion, thereby permitting the same motor 4| to provide power for both spinning and nodding.

Thus, also fixed to shaft 63 and driven therewith from motor 4| is a pinion '65 which meshes with and drives a gear 61 fioatingly supported on hub 5 Fixed to gear 61 is a further gear 69, which engages a pinion II fastened to a shaft 12 journaled in an extending arm 13 integral with 'yoke 53. Also fastened to shaft I2 is a pinion I4 ates with a driven clutch plate 11 to drive the latter when these two plates are in engagement.

Fixed to driven clutch plate 11 is an eccentric projection 19 cooperating with a slot 8| in a sliding member 83 which carries on its outer face a rack 85. Member 83 is guided by suitable guide slides 81 fastened to yoke 53 and is thereby constrained to move only perpendicularly with respect to the spin axis BI and yoke 53,

With clutch plates I5, 11 in engagement, the gear ratios are so chosen that driven clutch plate TI is rotated at a speed different from that of yoke 53, so that eccentric I9, cooperating with slot 8| in slide 83, will cause an oscillatory translational motion of slide 83 and rack 85. Meshing with rack 85 is a pinion 89 oscillated thereby. Pinion 89 is fixed to a shaft 9| journaled within yoke 53 and also carrying gear sectors 93 fixed thereto. Sectors 93 engage with cooperating gears 95 fixed to member 51 carrying parabola 59, and thereby the oscillatory rotational motion of pinion 89 is transferred to parabola 59, which is thereby caused to nod about axis 55. Accordingly, this nod motion combined with the spin motion causes the axis of parabola 59 to sweep out a spiral cone in space, whose outermost limits are determined by the maximum amount of nod as measured with respect to the spin axes.

Preferably the nod and spin rates are so adjusted that energy may be radiated to or received from every point of the conical solid angle within which scanning occurs. For this purpose, the pitch of the spiral, which may be defined as the angular separation between consecutive layers of the spiral, and is therefore equivalent to the change in nod angle per spin revolution, is chosen I to be no larger than the angular width of the radiation transmitting or receiving pattern formed by parabola 59. For example, a suitable radiation pattern width has been found to be 4 degrees. Accordingly, the scanner must not change more than 4 degrees in nod for each spin revolution. Suitable rates of rotation have been i'qund to be 1200 R. P. M. for spin and 30 complete revolutions per minute for nod. In this way a complete cycle comprising two spiral scans, one outward and one inward, over the desired conical solid angle is produced each two seconds, and each spiral scan comprises 20 complete spins. The extent of the conical solid angle may be suitably selected by determining the eccentricity of eccentric in 19 to produce a suitable range of nodding motion, or by properly choosing the gear ratios of sectors 93 and pinions 95. Thus, if it is desired to scan over a complete hemisphere, the system would be adjusted so that the nodding motion of parabola axis 60 takes place between degrees and 90 degrees with respect to the spin' axis. For smaller solid angles the limitation in nod would be correspondingly restricted.

The system thus far described, therefore, is capable of performing spiral scanning over a predetermined selected conical solid angle whose axis is. adjustable in azimuth and elevation. In order to suitably synchronize an indicator with this scanning motion it is desirable to transmitthe instantaneous position of the parabola in terms of its spin and nod components to the indicator.

For this purpose a self-synchronous transmitter 91, ofany suitable type, such as the Selsyn, Autosyn, or Telegon type, is coupled directly to the nod axis 55, as by suitable gears 99, to

provide signal currents corresponding to the position of the parabola in nod.

In view of the fact that this nod transmitter 91 must be fixed to spinning yoke 53, it is necessary to provide suitable slip rings for connecting these currents to external circuits. Such slip rings are shown atIUI, fixed to hub 5i and gear 48, and therefore fixed with respect to transmitter 91. These slip rings may therefore be connected to transmitter 91 by suitable conductors (not shown). Stationary brushes (not shown) mounted within housing 29 may be provided for conducting these currents to the external circuits.

In order to transmit the instantaneous spin position of the parabola to a distant point, a spin transmitter I03, which maybe of the same type as nod transmitter 91, is suitably coupled to the spinning part of the system as by suitable gears I05 and H11. No slip rings are necessary for transmitter I03 since it is fixedly mounted with respect to housing 29.

In order to transfer from spiral scanning to circular scanning, as described above, it is necessary in the present instance to interrupt the nod motion of the parabola at the proper point in its cycle of nod. For this purpose there is provided mounted on housing 29 a control solenoid. I99 whose coil is fixed to housing 29. The armature III of solenoid I09 is fastened to a ring Iii as by a rod II5. Ring I I3 is adapted to slide axially along housing 29, and will be so actuated. as to move toward parabola 59 upon energization of solenoid I09. If desired, a plurality of solenoids I09 may be disposed symmetrically about housing 29 to produce a proper axial motion of ring I I3.

Carried on yoke 53, as by a suitable bracket III, is a slidable rod II9 having at one end a roller I2I which normally rolls about ring H3. Roller I2I,'is urged against ring Iii! by means of a spring connected between arm I iii and. bracket 1, this spring not being shown in the view taken. Arm H9 at its other end is pivoted to a bell crank E23 having a. pivot I25 ilxed to the yoke 53. The other end of bell crank I23 actuates an interposing knife member IZ'I.

It will be clear from the above description that energization of solenoid I09 will push ring II3 forward, thereby pushing upon arm I II) no matter what the position of yoke 53 might be at the moment of energization, and hence, rotating bell crank I23 and pushing interposing member i2? toward the spin axis,

Interposing member IZ'I operates to separate driving clutch plate 15 from. the driven clutch. plate 'I'I. These two clutch plates and II are connected to move together by means o1: a pin I3I which is slidably mounted in driven clutch plate I1 and engages a slot or recess I32 on driving clutch plate I5 to thereby couple the two clutch plates together. Pin I3I is normally urged toward plate I5 and held within recess I32 by a suitable spring, (not shown).

Operation of interposing member I27! acts to remove pin I3I from its recess in driving clutch plate I5 and thereby releases driven clutch plate 11 from its driving source. Thus, pin I3I is formed with a tapered or slanted notch I34. The end of member I2! is also tapered in a similar fashion. When member IZI is moved toward spin pull itself out of recess I32. Plate II is therefore no longer supplied with driving power, and. a friction brake I33, which continuously engages clutch plate 'I'I, under the action of suitable spring I35, is thereby permitted to immediately stop clutch plate 11' in its rotation with respect to yoke 53. Thereafter clutch plate IT does not move with respect to yoke 53, but spins with it. Hence, eccentric I9 has no relative motion with respect to slide 83, and the nodding motion of the parabola 59 is interrupted.

The relationship between the position of eccentric I9 and slide BI is so chosen that when pin I3I comes into the position wherein it is engaged by interposing member I21, parabola 59 will be at the position of nod at which it is desired to stop the nodding motion. In this way the spiral scanning may be converted into circular scanning by remote electrical energization of solenoid I09, Without affecting in any way the spinning motion of parabola 59 or its orientability in elevation and azimuth.

It will be clear that the present scanning device need not be restricted to the transmission or reception of radio energy, but may be used to 7 transmit or receive other forms of energy, such as light, sound, infra-red rays, etc.

In view of the multiplicity of axes of rotation of the system it is necessary to provide special devices for introducing the ene gy to be radiated to or for abstracting energy from the parabolic refiector 59. The present device is especially adapted for use with ultra high frequency radiant energy, which can be conveniently conducted by means of hollow wave guides, although it is to be noted that the system is in no way so restricted and that concentric transmission lines or other types of conductors may be used, if desired. However, for the purpose of illustration; the present system has been illustrated as using hollow wave guides for conducting high frequency radiant energy.

Thus, a wave guide I39 leading from the energy source, or to the receiver, is conducted to the base I of the apparatus. Preferably such a wave guide is rectangular in form for convenience of construction and use, and to provide desirable electrical characteristics, although it may be of any other suitable shape. At the base 1 wave guide I29 is connected to a circular wave guide I II concentrically situated with respect to the azimuth axis 3. Suitable types of wave guide couplings for converting from a rectangular wave guide I39 to a circular wave guide I lI are shown in copending application Serial No. 429,494, for Directive antenna structure, filed February 4, 1942, in the name of R. J. Marshall, W. L. Barrow, and W. W. Mieher, and in copending application Serial No. 447,524, for High frequency apparatus, filed June 18, 1942, in the names of W. W. Mieher and J. D. Mallett.

Circular wave guide ItI is fixed to the base 1. A cooperating wave guide I43 is provided fixed to the mount I which, as has been described, is rotatable with respect to base 1 about azimuth axis 3. Therefore,'between wave guide sections MI and M3 there is provided a rotatable joint I45 also described in above-mentioned copending applications Serial Nos. 429,494, and 447,524.

Wave guide I93 is again converted by similar waves to a rectangular wave guide ml, which is then conducted to the elevation axis 21, at which point it is again converted to a circular wave guide I 89 coaxial with axis 21. This guide I49 is connected as by a rotatable joint I5I to a wave guide section I53 fixed to the spin housing 29. Similar converting devices and rotatable joints are provided about the spin axis SI and the nod axis 55, eventually leading the radiant energy to the terminating device or antenna within parabola 59. Suitable forms of termination are also shown in copending application Serial No. 429,494.

It is to be noted that any suitable type of high frequency energy conducting apparatus may be provided to energize the radiator 59, the above described system merely being one type which has been found to be suitable.

Figure 2 shows a scanning device functioning similarly to that of Figure 1. In this instance, however, the nod axis and elevation axis have been combined into a, single axis such as axis I50, alternatively utilized as a nod axis and as an elevation axis. Thus, parabolic reflector 59 is fastened to a shaft I52 coaxial with an axis I50 and which is joui'nalled in a pair of arms I55 ex tending from a casing I51. As will be later seen, casing I51 is continuously rotating at the spinning speed, during the spiral scanning operation. At the same time, to produce the spin motion in a manner to be inter (lcucrllmd, sliull, I03 lI-I con on a hollow stanchion I69 fixed stationary. Accordingly,

tinuously oscillated about axis I50 thereby producing the nod component of motion of reflector 59.

The motive power for the scanning operation is produced from a suitable motor I59 carried in a relatively stationary housingIBI. Motor I59 is adapted to selectively drive a gear I63 or a gear I65, the selection being effected by means of a suitable remotely actuated clutch such as magnetic clutch I61. Gear I63 is floatingly mounted within housing I6I concentric with the spin axis 6I.' Fixed to gear IE3 is a sleeve I1I which passes through an opening I13 in the base of spin casing I51 and terminates in a gear I15. Stanchion I69 extends concentrically beyond gear I15 and terminates in a stationary gear I11. Gear I65 is floatingly mounted upon sleeve Ill and in turn is fixed to a sleeve I19 fixed to spin casing I51.

In this way, upon suitable actuation of clutch I61 to its spiral scanning position, gear [65 is continuously rotated by motor I59, gear I63 remaining stationary. This produces a continuous rotation of casing I 51 about the spin axis 6i. Journalled within casing I51 is a shaft I8I fixed to a gear I83 engaging with gear I15, now stationary. Shaft I8I drives one member of a suitable mechanical differential I85, another of whose members is actuated by means of a gear I81 engaging stationary gear I11. The third member I89 of difierential I drives a pinion I9I fixed to a second shaft I93 journalled within casing I51, and thereby rotates a flexible shaft I to which the parabola 59 is coupled, as by means of suitable gearing I 91, the parabola 59, now being made rotatable .about an axis 62 fixedly displaced from the parabola axis 60 by the amount of nod needed for circular scanning, as will be seen.

Thus, assuming that clutch I61 is in the position corresponding to the spiral searching operation, motor I59 will continuously rotate gear I65, sleeve I19 and easing I51 at the spin rate and about the spin axis. Gear I63, sleeve HI and gear I15 will be stationary. Gear I11 is also as casing I51 rotates about gears I15 and I11, a corresponding rotation of gear I83 and gear I81 will be produced. Hence two members of difierential I85 are driven. Differential l85 and its associated gearing are so arranged that under these conditions no rotation of gear I 9| and shaft I93 with respect to casing I51 is produced. Accordingly, flexible shaft I95 does not rotate and parabola 59 is fixed relative to shaft I53. However, spin motion is produced by the rotation of spin casing I51.

Also engaging with stationary gear I11 is a pinion I99 which actuates one member of a mechanical differential 20I. A second member 203 of differential 20I is actuated in accordance with the elevation control of the scanner as will be later seen, but during searching operations is maintained stationary. Accordingly, during searching, any motion of gear I99 will be transmitted directly to the third member 205 of differential 20I, which, through pinion 201, worm 209, worm wheel 2, link 2I3' and crank 2I5 serves to oscillate shaft I53 about the nod axis I50, producing motion of the parabola 59 in nod. Motion of pinion I99 is produced during searching by rotation of casing I 51 about stationary gear I11, thereby producing the nod component 01' motion of parabola, 59. The various gear ratios involved are so chosen and the link mechanism lI-I m) iiIYlIlIltIlIl that it suitable .lItllU-U ltllll rate 01' 9 nod is produced according to the requirements of the particular problem at hand. In this way, the same type of spiral scanning is produced to effect searching as described with respect to Figure 1.

Continuously engaging spinning casing I51 is a brake 2|! held against casing I51 by means of a suitable spring 2I9. It will be clear that a plurality of such brakes and springs will ordinarily be used symmetrically disposed about casing I 51. Brake 2I1 is insuflicient of itself to affect the motion of casing I51 during searching, when casing I51 is driven by motor I59. However, should casing I51 be disengaged from motor I59, brake 2 I1 would be immediately effective to stop rotation of the casing I51.

Thus, upon actuation of clutch I61 to the opposite or tracking position, gear I65 is no longer driven from motor I59. Accordingly, the source of power is removed from casing I51, which is immediately brought to a standstill by brake 2 I1.

At the same time, gear I63, sleeve HI and gear I15 are set into rotation. Since casing I51 is no longer rotating, member I81 of differential I05 is no longer actuated and is held motionless by fixed gear I11. Accordingly, the rotation of gear I15 is transmitted to gear I83, shaft I8I through difierential I85 to gear I9I and through flexible shaft I95 to the parabola 59 thereby maintaining the spinning motion of parabola 59 either at the same rate as the previous spinning motion, or at a higher rate as may be desired. It will be noted that parabola 59 now rotates about an axis 62 which is not necessarily coincident with spin axis 6|.

The immobilizing of casing I51 also causes gear I99 to stop rotating. Since member 203 of differential 20I is also motionless, no motion is transmitted through gear 201 and thereby to shaft I52. Accordingly, the motion of parabola 59 in nod has been stopped and the only resultant motion is the spinning motion of parabola 59 about its new spin xis 62, which in this instance, may be difierent from the normal axis of spinning 6| by virtue of the fact that the nodding motion may be interrupted at any desired point.

In order to produce the very small circular scanning described with respect to Figure 1, preferably the axis 60 of the beam radiated from or received by parabola 59 is offset slightly with respect to the new spin axis 62 in order that the beam may sweep through the narrow circular cone described above.

It is usually desirable to interrupt the spiral searching scanning and initiate the circular tracking scanning at an instant such that the axis of the resulting circular scanning will coincide with the orientation of the distant object to be detected.

In order to accomplish this, the entire device thus far described while spirally searching is oriented in azimuth by a separate control to be described, until the azimuth of the spinning axis 6| coincides with the azimuth of the distant object. When this has been adjusted, the nodding motion is interrupted at the instant that the amount of nod corresponds to the elevation of the distant object, and thereafter the new circular scanning will have its spin axis 62 oriented towards the distant object as required.

To produce the desired motion in azimuth, the housing I6I is mounted for rotation about a vertical azimuth axis such as axis 3 and is fixed to a supporting member I64 to which is also fastened a gear I66. Gear I66 is adapted to be driven by a pinion I68, which, in turn, is actuated from a suitably controlled azimuth servo motor or other servo device I10 adapted to be controlled in any desired manner. Servo I10 may be of the form shown in Figure 1, or any other well-known type.

It will be clear that this azimuth control will remain effective during both the spiral searching scanning and the circular tracking scanning just described. However, after circular scanning is initiated, it is desirable also to be able to adjust or vary the orientation of the spin axis 62, in elevation. For this purpose, an elevation servo unit 22I, which may be of the same type as servo I10, actuates one member 223 of a compensating differential 225 to be described.

The output of differential 225 rotates a suitable sleeve 221 formed concentrically within supporting member I64. Sleeve 221 terminates in a gear 229 within housing I6I and its rotation is transmitted by way of a pinion 23I, shaft 233, gearing 235, shaft 231, gearing 239 worm MI and gear 243 to one member of a differential 245. A second member 241 of differential 245 is driven from gear I65 through an idler gear 249. The third or output member 25I of differential 245 actuates a gear 253 floating about the search spin axis 6|. Gear 253 actuates a pinion 255 fixed to a shaft 251 which is journalled within the spinning casing I51. Shaft 251 operates through gearing 259 and worm 26I to actuate the member 203 of differential 20I heretofore described.

During the spiral searching scanning operation servo 22I is generally stationary, which thereby immobilizes sleeve 221, gear 229, pinion 23I and member 243 of differential 245. At the same time, gear I65 continuously rotates member 241 of differential 245 through idler pinion 249. The resulting operation is such that gear 253 is rotated by differential 245 at the same rate and in the same direction as casing I51. Because of this, shaft 251 is rotating about search spin axis 61 at the same rate as pinion 253, resulting in no rotation of gear 255 and a consequent immobilization of member 203 of difierential 20I, whose effect has already been described.

Hence, during the spiral scanning, the stationary elevation control described above has no effect upon the operation of the scanner. However, after spiral scanning has been stopped and casing I51 rendered stationary, any motion of the output of elevation servo unit 22I will be transmitted through difierential 225, sleeve 221, gear 229, shaft 231, etc., to member 243 of diITerential 245. Gear I65 is now held stationary by the action of brake 2I1 on casing I 51, and accordingly the motion of member 243 of differential 245 will be transmitted directly to gear 253 and thence to gear 255, shaft 251, gearing 259, worrr 26I, difierential 20I, pinion 201, worm 209, worrr wheel 2| I, link 2I3, crank 2I5 to displace shafI I53 about the nod axis I5I. In this way, the orientation of parabola 59 with respect to the not ax'is I5I may be adjusted, and in efiect, the nod axis I5I becomes the elevation axis.

The radiant energy may be fed to or led frorr the antenna 59 in a manner similar to that described with respect to Figure 1, preferably using circular wave-guides wherever rotating joints an necessary and rectangular wave-guides wherever bends or angles are required. Such a wave-guidi system is shown in Figure 2 but need not be further described.

the scanner is rotated in azimuth about aXis 3, pinion 23I will walk around stationary gear 229, thereby producing rotation of shaft 233 and consequent change in elevation. T prevent this, differential 225 causes gear 229 to rotate by the proper amount to keep shaft 233 stationary, and thus compensate for the azimuth motion in its effect on elevation adjustment.

It will be clear that azimuth, spin and nodelevation self-synchronous transmitters may be suitably coupled to these respective axes to remotely indicate the instantaneous attitude of the scanner with respect to these axes, if desired.

If desired, gear I63 may be continuously driven from motor I59 at all times. This would cause a continuous rotation of parabola 59 about its spin axis 62, at the same rate as the rotation about axis 6I, thereby distorting the spiral scan slightly, but not materially, because of the small angle of the spinning of parabola axis 6| about spin aXis 62. In this case, clutch I61 would only act to engage or disengage gear I65 from motor I59, the operation otherwise being as described above.

For proper operation as described above, it is necessary that casing I51 be stopped with nod axis I50 substantially horizontal, and that the nod motion of parabola 59 be stopped at the proper elevation of the distant object. As described above, the scanner, while spirally searching, is preferably oriented in azimuth until the azimuth of search spin axis 6| is the same as that of the distant object, as shown on any suitable indicator, one type being described in the above-mentioned copending application Serial No. 441,188. As therein described, periodic pulses of radiant energy may be transmitted from the radiating system 59, being reflected by any objects within the scanning range. A cathode ray indicator is used in which an electron beam is spirally actuated in synchronism and correspondence with the motion of the scanner. Reception of a reflected pulse causes momentary brightening of the beam trace, indicating by its position on the cathode ray screen, the orientation of the distant object. The orientation of the search spin axis 6I corresponds to the center of the screen. Accordingly, the operator need merely actuate azimuth servo I10 until the azimuths of spin axis 6| and the distant object are the same. thereby assuring that when the scanner axis 60 sweeps across the object, the nod axis is horizontal. The operator must then stop the spiral scanning at the point where the scanner is oriented in nod toward the distant object. This may most simply be done by interrupting the spiral spin and nod at the instant that a reflected pulse is received, when, since scanner and object are already lined up in azimuth, the scanner nod position will be sub stantially identical with the elevation of the object.

One type of apparatus for producing this result is schematically shown in Figure 3, by suitable control of clutch I61. Thus clutch I61 has one terminal connected directly to one side 21I of a power line 213, the other terminal being connected to the other line side 212 through contacts 215 of a relay 211. During searching, relay 211 is energized through switch 219 in its left or search position, so that contacts 215 are open, thereby deenergizing clutch I61 and engaging gear I65 to be driven by motor I51 to perform spiral search scanning. When circular tracking scanning is desired, switch 219 is thrown to the right or tracking position, thereby placing relay 211 in series with contacts 285. These contacts are normally closed, so as to maintain searching, but are opened in any known manner in response to reception of a reflected pulse from the distant object, whereupon relay 211 is deenergized, closing its contacts 215 and energizing clutch I61, so that gear I65 is disengaged from motor I51, and is halted by brake 2I9. Energization of clutch I61 now causes motor I51 to drive gear I63 and perform the circular scanning already described. The control for contacts 285 may be of any well known type, and is preferably of the quick-open, delayed-close type, whereby circular tracking scanning is maintained so long as reflected pulses are received. Relay 211 is also preferably made to be quickopening and delayed-closing, to prevent needless chattering between searching and tracking. Thereafter tracking with the distant object in elevation and azimuth may be effected by suitable control of servos 22I and I10, respectively.

Figure 4 shows a modified circuit for performing the transfer between scanning and tracking, now replacing continuously acting brake 2I9 with a solenoid operated brake 2I8. Thus, clutch I61 has one terminal connected to side 21I of power line 213. The other terminal of clutch I61 is connected to side 212 of line 213 through contacts 215 of time delay relay 211, whose winding is adapted to be directly energized from power line 213 when transfer switch 219 is thrown in the left search position.

Time delay relay 211 is preferably of the quickopen, delayed-close type, and, upon its energization, clutch I61 is deenergized through opening of contacts 215. This occurs in the left or search position of switch 219. Under these conditions brake 2I8 is deenergized, since it is connected in series with switch 219 when in the tracking position and also in series with relay contacts 28I, whose energizing coil 283 has one terminal connected to line 21I and its second terminal connected through radio controlled contacts 286 to terminal T of switch 219.

Accordingly, in the searching position, clutch I61 is deenergized and brake 2I8 also is deenergized, resulting in the spiral scanning or searching operation described above. Upon switching to the tracking position of switch 219, clutch I61 is energized, thereby disconnectin the drive for the nodding motion as described above. However, due to the inertia of the various moving parts, spiral scanning will continue until brake 2I8 is energized. Brake 2I8 is under the control of contacts 28I of relay 283. This relay in turn is under the control of radio-controlled contacts 286. Contacts 286 are placed under the control of the received pulses, that is, are adapted, in a manner well known, to close only at the time when pulses are received from the distant refleeting object, and to remain closed for a fixed interval after the last pulse received.

Accordingly, before throwing the switch 219 to the tracking position, the operator will orient the scanner in azimuth by means of a suitable control of azimuth, servo unit I10 until the azimuthal orientation of the spin axis BI is the same as the azimuth of the distant object. Thereafter, he may throw the switch 219 to the tracking position at any desired moment. At the first instant after the switching operation that the parabola axis 66 is directed at the distant object, a reflected pulse will be received by the system and contacts 286 will close, thereby energiz ng relay winding 283 and closing its contacts 28I and so energizing brake 2I8 which thereupon stops the spiral scanning motion.

worm I12, thereby spinnin yoke I51.

It will be clear that in this position the nod displacement of the parabola axis 55 will be substantially the actual elevation of the distant object and that thereafter elevation control during the circular scanning used in tracking may be obtained by suitable adjustment about the nod axis under the control of the elevation servo 22I as described above.

Closing of contacts 286 also energizes a time delay relay 281 controlling a series of contacts 293, 295, 291, etc., which may serve to control the changeover operation from searching to tracking of the remaining parts of the system, such as the radio circuits, indicator circuits, servo circuits, etc., as described more in detail in copending application Serial No. 441,188. In this way there is provided a scanning unit similar in operation to that of Figure 1, but com bining nod and elevation axes into one axis.

It is to be noted that the device of Figure 2 reaches its greatest utility when scanning over a solid angle having a horizontal axis, in distinction to the device of Figure 1, wherein any solid angle within the azimuth and elevation range of variation of the device may be scanned. However, the device of Figure 2 need not be so restricted, since axis 3 may be oriented as desired. In such case, however, rotation about axis 3 is no longer true azimuth variation, an axis I50 no longer represents a true elevation axis, but rather instead of elevation and azimuth there are used two other independent coordinates having no well-defined description.

Figure 5 shows a still further modified scanner, useful mainly where the range of the instrument is to be restricted to a fixed hemisphere. Here the nod and elevation axes have been combined into one axis and the spin and azimuth axes have also been Combined into a single axis. The constructional details and type of operation of the scanner of Figure 5 are quite similar to that of Figure 2 and like parts will be given the same reference numerals.

Thus, a stationary stanchion I69 is provided preferably concentric with the now combined spin and azimuth axes BI and carrying a stationary gear I11 at its upper end. Rotatably supported on stanchion IE5 is a floating gear I53 fixed to a sleeve I1I at whose upper end is fastened a gear I15. Rotatably supported on sleeve I1I is a further gear I65 fixed to a sleeve I19 carrying at its upper end the spinning casing I51 shown in this instance as being formed simply of an open yoke rather than a closed housing as in Figure 2. Drive motor I59 in cooperation with electromagnetic clutch I61 is adapted to selectively drive either gear I63 or gear I55, according as tracking or searching is to be performed.

Considering for the moment the searching operation, clutch I61 is actuated to drive gear I65 from motor I 59 through differential I16, whose member I14 is held stationary by irreversible At the same time, gear I63, sleeve I1! and gear I15 are stationary, and therefore flexible shaft 195 is prevented from rotating in the manner described with respect to Figure 2. However, pinion I99 is causedto rotate, thereby driving through differential ZIJI, pinion 201, worm 2139, worm wheel 2t I, link 2I3 and crank 2I5 to operate the nod shaft I53 and thereby cause nodding of the parabola 59 about the nod axis I 50, at the same time that spinning is produced by rotation of spinning yoke I51 about the spin axis 8 I. In this manner, spiral scanning is performed.

lid

For tracking and circular scanning, clutch I51 is actuated to its other position and magnetic brake EH2 is momentarily energized, thereby stopping yoke I51 and rotating gear I53. Since yoke I51 is now stationary, pinion I99 no longer ro tates and both the spin motion of yoke I51 and the nod motion are interrupted. However, mo tion in elevation derived from elevation servo 22I through gearing 222, differential 255, gear 253 and pinion 255 causes control of the nod-elevation axis I53 in a manner already described with respect to Figure 2, brake ZIB by this time being deenergized.

Rotation of gear I63 now causes rotation of sleeve HI and gear I thereby rotating gear IBI and acting through differential I55 to rotate gear I91 and thereby flexible shaft I95 to spin the parabola 59 in its circular scanning about new spin axi 52.

In order to control the rotation of the parabola orientation in azimuth, azimuth servo I10 now drives a worm I12 engaging one element 1150f a differential I15. This serves" to rotate pinions I18 and I engaging gear I55 and thereby ad-- justs yoke I51 in azimuth. Combined azimuthspin and combined nod-elevation self-synchronous transmittei's may be provided here also.

From the foregoing, it will be seen that in transferring from searching to tracking the spinning motion of spinning yoke I51 must be stopped, but then yoke I51 must be left free for motion in azimuth. Accordingly, the braking ac tion must be only momentary. Also the nod mo" tion must be interrupted when parabola axis 55 is directed at the distant object as in Figure 2.

Figure 6 shows a suitable control circuit for producing these desired results, similar in many respects to Figure 4. Here again switch 21 51 when in the search position keeps clutch I 51 deener gized by energizing relay 211 which maintains contacts 215 open. Upon switching to the track ing position of switch 219, relay 211 is deeIl1- gized, closing contacts 215 and energizing clutch I81 to convert from search to track. When radio-controlled contacts 285 similar to those oi Figure 4 are closed, relay 283 is energized, con-- tacts 288 of relay 291 being normally closed. Thereby contacts EEII are closed, energizing brake 2I8 and stopping the spin motion of yoke I51.

Closing of radio contacts 285 also. energizes time delay relay 281, whose contacts 25%? close after a predetermined time interval, thereby euergizing relay ml, which. acts to open contacts 288 as wellas to close contacts 293, 295, etc. Opening of contacts 288 deenergizes brake 215, which therefore acts only momentarily, for a time suificient to fully stop yoke I51. Thereafter yoke I51 is free to be actuated by azimuth servo I1 5 for azimuth tracking control.

Here also, gear I63 may be continuously operated by motor I 59, in the same manner as with respect to Figure 2.

Figures '1 and 8 illustrate another method of correctly determining the exact point at which the spiral searching scannin should be converted to circular tracking scanning. Thus, it may be desirable to determine in advance the orientation, in azimuth and elevation, for example, at which it is desired to stop the spiral scanning of the scanner of Figure 5 and convert its motion to circular scanning for tracking purposes. Thus, in Figure '7 is shown a manually orien'table direction-indicating member 50 I, having a handle 3133 adapted for manual manipulation. Direction-indicating member 301 is adapted to be oriented about a horizontal axis 305 corresponding to an elevation axis, and a vertical axis 301 corresponding to an azimuth axis. Coupled to each of these axes are respective self-synchronous transmitters 309 and -3I I of any of the well-known types, which are thereby adapted to transmit to a remote point signal currents representing the respective orientation'of direction indicator 30I in elevation and azimuth.

In operation, the required or desired orientation of the scanner of Figure 5 may be determined by any suitable means, such as the oathode ray indicator described above. After this orientation is determined, member 30I is oriented correspondingly. This may be done by means of suitable scales indicating angular elevation and .angular azimuth, or by matching member 30I with the indication of the cathode ray indicator in any suitable manner.

As shown in Figure 8, the elevation transmitter 309 is connected to the nod self-synchronous device 3I3, acting in this instance as a signal generator, to produce in its output an alternating voltage having a magnitude corresponding to the difierence in orientations of scanner axis 60 and member 30I in elevation. I In a similar manner, azimuth transmitter 3 is connected to the spin self-synchronous device 3I5 of the scanner of Figure 5, serving also as a signal generator producing an alternating voltage havingan amplitude corresponding to the difference in the orientations of the scanner axis 60 and member 30I in azimuth.

These two displacement or difierence voltages are rectified in suitable respective reotifiers, such as 3" and 3I9, to obtain corresponding unidirectional voltages which thereupon maintain respective relay windings 32I andv 323 energized as long as the orientations differ. Relay winding 32I cooperates with a relay armature 325 and two fixed contacts 321 and 329. While relay winding 32I is energized, armature 325 breaks contact with fixed contact 321, thereby maintaining in an open condition the control circuit for clutch I61 connected to wires 33I, and deenergizing clutch I61 to effect spiral searching. Upon deenergization of relay winding 32I, armature 325 makes contact with fixed contact 329, to condition the energizing circuit of brake 2I8, as will be seen. Also, armature 325 makes contact with contact 321 and energizes clutch I61.

Relay 323 cooperates with armature 332 and a fixed contact 333. When relay winding 323 is energized, armature 332 and contact 333 are open-circuited. Upon deenergization of relay winding 323, armature 332 makes contact with fixed contact 333. When contacts 325, 329 and 332, 333 are closed, the control circuit of brake 2IB, connected thereto as by wires 334, is then closed and brake 2I8 becomes energized.

From the above it will be clear that the voltage or current applied to relay winding 32I can become zero only when the nod position of parabola 59 is the same as the elevation setting of member 30I. When this occurs, armature 325 of relay 32I closes the clutch control circuit by engaging fixed contact 321. By this action, motor I59 is disengaged from spin yoke I58 and parabola 59 becomes actuated by flexible shaft I95, as described above, to start its tracking scanning. However, due to the inertia of the various parts of the system, the spin motion about-axis 6| will continue for several revolutions. During this time the output of spin signal generator 3 I5, and accordingly the current supply to relay wind- 16 ing 323, will vary from maximum to zero several times as the azimuthal position of parabola 59 passes through the position of correspondence with that of member 30I. If the speed of rotation of scanner 59 about spin axis 6| at the instant the current in relay winding 323 becomes zero is quite rapid, armature 332 does not have time to fall out before it is again held in by the reenergizing of relay winding 323. However, due to frictional effects, the speed of rotation is continually decreasing and eventually a point is reached at which this speed is slow enough to permit armature 332 to make contact with fixed contact 333. When this is done, since contacts 325 and 829 are already closed, brake 2I8 will be energized and the spinning motion about axis 6| will be instantly stopped. In this way brake 2I8 need not absorb the full rotationalspin energy. Since at this moment both the signal output from nod signal generator 3I3 and speed signal generator 3I5 are zero, it will be clear that the orientation of the parabola 59 will be substantially the same as that of member 30I, the only difference being occasioned by the change in nod caused by the coasting period. This may be made small by providing a suitable damping or friction brake .continuously engaging the spinning part of the device, as in Figure 1. The coasting period is desirable in order to prevent large stresses due to too rapid deceleration, and to assure accurate stopping. In this manner the scanner of Figure 5 may be converted from the spiral searching scanning to circular tracking scanning at any desired orientation under the control of direction-indicating member 30I. A suitable device for deenergizing brake 2I8 after the scanner has begun conical scanning is also provided as in Figure 6.

It will be clear that it is not necessary to use the particular type of control member shown in Figure '1. Thus, control member 30I may be replaced by a telescope, sound locator, gun director, a computing gun sight, or any other orientable device.

Figure 9 shows a modification of the scanning system of Figure 5 adapted to produce the same functions in a somewhat simpler manner. In

this modification the changeover clutch I61a. is

provided with two energizing coils, such as I36 and I68. When coil I68 is energized, floating gear 200 is actuated from gear 202 driven from motor I59, corresponding to the searching operation. When coil I66 is energized gear 200 is instead actuated from worm wheel I82 driven from the azimuth servo I14, corresponding to the tracking operation. During searching, motor I59 actuates gears 202 and 200 and thereby drives gear I65 and the yoke I51 carrying the nod axis I53 as before, and thus providing the spinning motion of parabola 59. At the same time motor I59 drives gear I63, sleeve HI and gear I15 at the same angular velocity as yoke I51. Accordingly, gear I83 meshing with gear I15 and having its bearing I84 fixed to yoke I51, will not be rotated, since its shaft I86 is carried around gear I15 by yoke I51 at the same speed as the speed of rotation of gear I15 itself. Accordingly, for this condition of operation flexible shaft I fixed to gear I83 will not be rotated, and the parabola 59 will remain stationary about axis 62.

The motion of spinning yoke I51 causes gear I99, mounted on a shaft I98 rotatably mounted within yoke I51, to rotate about a stationary gear I11 fixed to stationary stanchion I69. This rotation of gear I99 is led through differential.

the nod motion of the parabola in a manner similarto that shown in Figures 2 and 5, it being understood that the third member 203 of differential 20I is held stationary by means of the elevation servo 22I as described with respect to prior Figures 2 and 5.

To convert to the tracking operation, clutch section I68 is deenergized and. clutch section I66 is energized, the energizing means being as shown in Figures 3, 4, 6, or 8. Under this condition of operation motor I59 still drives gear I63 and hence gear I15 continues to rotate. However, yoke I5! is no longer continuously driven from motor I59 and has had its rotation stopped by means of a brake similar to brake 2'I8 of the preceding figures. Accordingly, the spinning motion of yoke I51 is interrupted, and thereby the nod motion is also interrupted, in the manner already described with respect to Figures 2 and 5. However, rotation of gear I15 now rotates gear I83 actuating flexible shaft'l95 and gearing I91, spinning the parabola about axis' 62 to provide the circular tracking scanning of the same type as that produced by the preceding Figures 2 and 5. Control of the scanner orientation during tracking in azimuth is derived from the azimuth servo I" which actuates worm I12, worm wheel I82 and gear 200 (clutch section I66 now being energized) whereby the position of the yoke I51 may be adjusted under the .control of azimuth servo I14. The elevation servo 22I operates as before through worm and worm wheel arrangement 222, differential 245, gear 253, gear 255, and worm and worm wheel arrangement 26I, 203 to control difierential 20I and thereby through gear 207, worm 209,

worm wheel 2I I, link 2I3 and crank M5 to control the'positioning of the spin axis 62 in nod about axis I53.

Suitable nod-elevation and spin-azimuth selfsynchronous transmitters may be coupled to axes I53 and 62 or 6|, as desired.

It will be clear that, if desired, stanchion I69 may be made rotatable about an axis perpendicular thereto and azimuth servo I14 may be made effective to control the position of stanchion I69 (and hence spin axis 6|) about this perpendicular axis in the manner similar to Figure 2 so that the simplification efiected by the device of Figure 9 may be applied to the device of Figure 2, as well as to Figure 5, as illustrated.

The control of clutch I6la may be the same as in Figures 3, 4, 6, or 8, merely requiring a further contact on the clutch control relay described to cause energization of clutch section I66 at the same'time that section I68 is deenergized, and vice versa.

As many changes could be made in the above construction and many apparently widely diifer-. ent embodiments of this invention could be made- =without departing from the scope thereof, it is L intended that all matter contained in the above mounting said antenna means'on said yoke for oscillationhbout a-first axis, means for rotating said yoke at a predetermined rate about a second axis perpendicular to said first axis,

a clutch having a driving member and a driven member each rotatably mounted concentrically with respect to said second axis, means for actuating said driving member from said rotating means at a rate difierent from said predetermined rate, an eccentric and slide arrangement actuated by said yoke and said driven member for producing an oscillatory translational motion with respect to said yoke, means for oscillating said antenna means about said first axis by said last motion, a pin slidably mounted in one of said clutch members and normally engaged in a recess in the other of said members for engaging said two clutch members, a slanted notch formed in said pin, a knife member slidably mounted in said yoke and adapted when actuated to withdraw saidpin from said recess upon interaction with said slanted notch, stationary means for actuating said knife member to disengage said clutch and thereby stop said oscillatory motion. and means for orienting said second axis in azimuth and elevation.

2. A scanning device comprising directional antenna means, a yoke, means for pivotally mounting said antenna means on said yoke for oscillation about a first axis, means for rotating said yoke at a predetermined rate about a second axis perpendicular to said first axis, a clutch having a driving member and a driven member each rotatably mounted concentrically with respect to said second axis, means for actuating said driving member from said rotating means at a rate different from said predetermined rate, an eccentric and slide arrangement actuated by said yoke and said driven member for producing an oscillatory translational motion with respect to said yoke, means for oscillating said antenna means about said'first axis by said last motion, means for disengaging said clutch whereby said oscillatory motion is halted, and means for orienting said second axis in azimuth and elevation.

3. A scanning device comprising directional antenna means, a support, means for pivotally mounting said antenna means on said support for oscillation about a first axis, means for rotating said support at a predetermined rate "about a second axis perpendicular to said first 4. A scanning device comprising directive antenna means. means for pivotally mounting said antenna means for oscillation. about a first axis, means for spinning said first axis about a second axis perpendicular thereto, means for simultaneously oscillating said antenna means about said first axis, and means for stoppingsaid oscillatory motion while retaining said spinning motion.

5. A scanning device comprising directive an tenna means, means for pivotally mounting said antenna means for oscillation about a first axis, means for spinning said first axis about a second axis perpendicular thereto, and means for simultaneously oscillating said antenna means aboutsaid first axis.

6. A scanning device comprising directive antenna means, means for mounting said antenna means for rotation about a first axis rigidly fixed with respect to the directivity axis of said antenna means, means for pivotally supporting said first axis for oscillation about a second axis perpendicular to said first axis, means for rotatably supporting said second axis about a third axis perpendicular to said second axis, means for rotating said antenna means about said third axis and for oscillating said first axis about said second axis while maintaining said antenna means stationary with respect to said first axis, means for orienting said third axis in azimuth, means for stopping said rotation and oscillation at a predetermined orientation of said antenna means with said second axis substantially horizontal and for simultaneously initiating rotation of said antenna'means about said first axis, and means for adjusting the orientation of said antenna means in elevation about said second axis.

'7. A scanning device comprising directive antenna means, means for mounting said antenna means for rotation about a first axis rigidly fixed with respect to the directive axis of said antenna means, a yoke, means for pivotally mounting said first axis in said yoke for oscillation about a second axis perpendicular to said first axis, means for rotatably mounting said yoke about a third axis perpendicular to said second axis, means for rotating said yoke about said third axis and for oscillating said first axis about said second axis while maintaining said antenna means stationary with respect to said first axis, means for stopping said rotation and oscillation at a predetermined orientation of said antenna means and for simultaneously initiating rotation of said antenna means about said first axis, means for adjusting the orientation of said antenna means in elevation about said second axis, and means for adjusting the orientation of said antenna means in azimuth about said third axis.

8. A scanning device, comprising directing antenna means, means for mounting said antenna means for rotation about a first axis fixed with respect to the directivity axis of said antenna means, means for pivotally mounting said first axis for oscillation about a second axis perpendicular to said first axis, means for rotatably mounting said second axis about a third axis perpendicular to said second axis, means for rotating said antenna means about said third axis and for oscillating said first axis about second axis while maintaining said antenna means stationary with respect to said first axis, and means for stopping said rotation and oscillation at a predetermined orientation of said antenna means and. for simultaneously initiating rotation of said antenna means about said first axis.

9. A scanning device comprising directive antenna means, means for mounting said antenna means for rotation about a first axis, means for oscillating said first axis about a second axis, means for spinning said second axis about a third axis while maintaining said antenna means stationary with respect to said first axis, means for interrupting said spinning and oscillation and for initiating rotation about said first axis, and means for adjusting the orientation of said first axis about said second axis.

10. A scanning device as in claim 9, further including means foradjusting the orientation of said antenna means about said third axis.

11. A scanning device comprising directive antenna means, means for nodding said antenna means about a nod axis, means for simultaneously spinning said antenna means about a spin axis, and means for interrupting said nod motion while maintaining a spin motion of said antenna means.

12. A scanning device as in-claim 11, further including means for adjusting the position of said antenna means about said nod axis.

13. A scanning device as in claim 11, further including means for adjusting the position of said antenna means about said spin axis.

14. A scanning device as in claim 11, further including means for adjusting the position of said antenna means about said nod and spin axis.

15. A scanning device as in claim 11, further including means for converting said nod axis to an elevation axis and for adjusting said antenna means about said elevation axis.

16. A scanning device as in claim 11, further including means for converting said spin axis to an azimuth axis, and means for adjusting said antenna means in azimuth about said azimuth axis.

17'. A scanning device as in claim 11, further including means for converting said nod axis to an elevation axis and said spin axis to an azimuth axis, and for adjusting said antenna means in elevation and azimuth about said axis.

18. A scanning device comprising orientable means, means for nodding said orientable means about a nod axis, means for simultaneously spinning said orientable means about a spin axis, and means for interrupting said nod motion while maintaining a spin motion of said orientable means.

19. A scanning device comprising a directive antenna adapted to radiate a lobe of radiant energy, first scanning means operative on said antenna, to sweep said lobe recurrently through a first predetermined path confined within a solid angle, and second scanning means operative on said antenna to sweep said lobe recurrently through a second predetermined path confined within a second solid angle.

20. A scanning device comprising a directive antenna adapted to radiate a lobe of radiant energy, comprising first scanning means operative on said antenna to sweep said lobe recurrently in a path generating a spiral cone, and second scanning means operative when said first scanning means is inoperative to sweep said lobe recurrently in a path generating a relatively slender circular cone of fixed apex angle.

21. Apparatus comprising an orientable device adapted to project a lobe of energy, first scanning means operative on said device to sweep said lobe recurrently through a spiral conical path, second scanning means operative on said device to sweep said lobe through a small circular arc, power means for actuating said scanners, and means for rendering one of said scanners inoperative while the other is operative.

22. A directive antenna adapted to scan a space confined Within a solid angle, comprising a paraboloidal radiant energy reflector, means for spinning said reflector continuously about a first axis, means for oscillating said reflector about a transverse axis, and means for locating said reflector at predetermined positions about said transverse axis.

23. Scanning means comprising a paraboloidal reflector, means for spinning said reflector about an axis initially substantially aligned with the axis of said reflector, and means for oscillating said reflector axis through a limited are from said spin axis about a transverse axis.

24. A scanning device comprising a directive antenna adapted to project a lobe of radiant energy and power means for sweeping said lobe through a solid angle in space, and braking means responsive to energy reflected from an irradiated object for stopping the motion of said lobe when said lobe is directed substantially on said object.

25. A scanning device comprising a directive antenna adapted to project a lobe of radiant energy, first scanning means adapted to sweep said lobe through successive portions of a solid angle in space, second scanning means operative when said first scanning means is inoperative, to sweep said lobe through a narrow zone of said solid angle, and control means responsive to radiant energy reflected from a scanned object adapted to render said first scanning means inoperative.

26. A scanning device comprising a directive antenna adapted to project a lobe of radiant energy, first scanning means adapted to sweep said lobe through successive portions of a solid angle in space, second scanning means operative when said first scanning means is inoperative, to sweep said lobe through a narrow zone of said solid angle, a control device having a directional indicator adjustable to predetermined positions denoting the successive positions of said lobe, and means actuated by said control device for rendering said first seaming means inoperative when said lobe reaches a predetermined position relative to said indicator.

27. A scanning device comprising a paraboloidal solid angle, and means for spinning said reflecr tor about a fixed axis eccentrically disposed with: respect to said lobe, but substantially aligned with the axis of said reflector.

28. In the method of scanning, the steps comprising revolving and oscillating the directive axis of an energy radiator through successive portions of a solid angle in space to locate a target, and upon receiving radiant energy reflected from said target, confining the sweeping motion of said radiator to a relatively narrow solid angle adapted to enclose said target.

29. In the method of locating and tracking targets, the steps comprising sweeping the directive axis of an energy radiator through successive portions of a solid angle to locate a target therein, discontinuing such sweeping movement so as to locate said axis substantially on said target in response to radiant energy reflected along said axis from said target, and thereupon sweeping said directive axis about an axis eccentric to said directive axis so that the directive axis generates a cone of revolution adapted to enclose said target.

LEON A. MAYBARDUK. WALTER W. MIEHER. STEPHEN J. ZAND. GIFFORD E. WHITE. 

